I have been using Batocera for one year with a Pi 3B and a few months later with a Pi 5, and I can tell you a few things that I didn’t like:
There were no overheating or undervolting warnings. There was no throttling when the system was overheating They are offering 64-bit images for the 3B with the Sway window manager, which adds too much load to a weak board. They are updating everything in every new release without enough testing, relying too much on users for bug reports as a result many bugs. You don’t have the ability to update or downgrade cores, so if a bug appears, you have to wait for the next release. System was running 7-10 degrees hotter than RetroPie. I had performance issues with PS1 games with enhanced resolution. For example, Colin McRae 2 is running at 60 fps with Retropie but is having frames drop in B. The same issue occurs with Dolphin on Pi5, games that run at full speed on Retropie are unplayable in Batocera.The big plus of Batocera is its simplicity and the feature-rich version of EmulationStation. Try them both and choose the best for you